The vast majority of the coins that Heritage sells have been professionally graded (certified) and encapsulated (slabbed) by a third party grading service such as NGC, PCGS, ANACS or ICG. When a coin has been professionally graded, both the buyer and the seller know that a third party has determined the coin to be authentic and assigned a numerical grade, and thus disagreements about the quality of the coin, although not necessarily eliminated, are drastically reduced.
As a collector, there are certain times that you should get coins professionally graded, and other times when professional grading is not necessarily a good idea. Because grading costs money, you need to determine whether it is worth the price to grade the coin. We see slabbed coins all the time that aren't worth the cost of getting them graded and slabbed.
The simple answer is that you should get your coins professionally graded if you stand to benefit from the process. This can take several forms:
You stand to gain monetarily from having the coin graded. If your coin is raw (not in a slab), and you believe that the value of the coin in a slab would be more than the value of the coin out of the slab plus the cost of grading the coin, then you should seriously consider getting the coin graded. This often applies to coins that have drastic increases in value with just a slight rise in grade.
The coin needs to be authenticated. There are many fakes floating around of rare and key date coins; in fact, it is a truism that there are more fake 1916-D dimes than real ones. If you have a coin that is rare, or if you have a coin that is frequently encountered as a phony, consider getting your coin graded. Grading companies will not knowingly encapsulate a counterfeit or altered coin.
The coin needs to be attributed. If you suspect that you have a rare or unusual variety of a coin, some grading services will attribute the die variety for an additional fee.
You are selling your better coins. It is much easier to sell most coins through Internet venues if they are graded and imaged, much like the coins offered for sale in Heritage auctions.
Times when you should not get your coin professionally graded include:
Your coin is obviously worth less than the cost to get it graded. It's not a good idea, for example, to get a circulated 1936 nickel professionally graded, as the coin is likely to be worth only about fifty cents.
The cost of grading is more than what you stand to gain by getting your coin graded. While this applies to coins that are worth only a little bit more than the cost to grade, it can also apply to some higher value coins that have very small differences in values as their grades rise.
World Coins should probably not be professionally graded unless their authenticity is in question. The market for certified world coins is generally not as robust as the market for certified US coins.
Note that it can make quite a difference in some cases where you get your coins graded. Some grading companies will not grade coins with problems, and others, notably ANACS, will grade almost any authentic coin, but determine a net grade based on both the details on the coin and any problems the coin may have. Resale values can also differ, sometimes quite greatly, based on the grading service and their general acceptance within the marketplace.
Do I need to have my coins professionally graded before I consign to Heritage?
No. Heritage will work to get you the top possible dollar for your consignment, and part of this process involves submitting coins to the proper grading service when it is worth your while. We submit coins for grading all the time, and in most cases it is easier for a potential consignor to send coins to us before they've been professionally graded than to get the coins graded on their own first. As the leading rare coin dealer in the world, we get volume discounts from the grading services, and we will apply these discounted fees to your consignment settlement. Coins that we believe should not be certified will generally be grouped as appropriate and sold in our invitation-only Gallery sales.